JP5077614B2 - Power supply system and control method of power supply system - Google Patents

Description

  The present invention relates to a power supply system including a fuel reforming fuel cell and a control method of the power supply system.

  In recent years, with the growing interest in environmental and energy issues, the practical use and popularization of power supply systems equipped with fuel cells with extremely low environmental impact and extremely high energy conversion efficiency as the next-generation mainstream power generation system Research and development for the FIG. 7 is a block diagram illustrating a configuration example of a power supply system including a fuel reforming fuel cell. The fuel cell system shown in this figure includes a control unit 100, a fuel tank 101, an evaporator 102, a reformer 103, a CO remover 104, a power generation cell 105, pumps P1 to P3, flow meters F1 to F5, and valves V1 to V5. Is provided.

  The evaporator 102 vaporizes the power generation fuel (methanol) supplied from the fuel tank 101 by the pump P <b> 1 and sends it to the reformer 103. The flow rate of the power generation fuel injected into the evaporator 102 is adjusted by the valve V1 and measured by the flow meter F1. The evaporator 102 is provided with a temperature sensor TS, and the temperature measurement value T of the temperature sensor TS is supplied to the control unit 100. The reformer 103 generates a reformed gas containing hydrogen from the vaporized fuel supplied from the evaporator 102. The reformer 103 is provided with a temperature sensor TS, and the temperature measurement value T of the temperature sensor TS is supplied to the control unit 100.

  The CO remover 104 mixes the air introduced by the air pump P3 and the reformed gas generated by the reformer 107, removes carbon monoxide CO from the reformed gas based on the selective oxidation reaction, and generates the power generation cell 105. To supply. The flow rate of air that is ventilated to the CO remover 104 is adjusted by a valve V4 and measured by a flow meter F4. The CO remover 104 is provided with a temperature sensor TS, and the temperature measurement value T of the temperature sensor TS is supplied to the control unit 100.

  The power generation cell 105 includes a fuel electrode formed on one surface of the electrolyte membrane MEA and an air electrode formed on the other surface, and is contained in the reformed gas supplied from the CO remover 104 to the fuel electrode. Electric power is generated by an electrochemical reaction between hydrogen and oxygen in the air introduced into the air electrode by the air pump P3. The flow rate of air introduced into the air electrode side of the power generation cell 105 is adjusted by the valve V5 and measured by the flow meter F5.

  The combustor 106 is configured such that fuel injected from the fuel tank 101 by the pump P2 and off-gas (unreacted reformed gas containing hydrogen) discharged from the power generation cell 105 are introduced into the air introduced by the air pump P3. Mixing and catalytic combustion are performed, and each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is maintained at a predetermined temperature by the combustion heat. The flow rate of air introduced into the combustor 106 is adjusted by the valve V3 and measured by the flow meter F3.

  The control unit 100 manages the hydrogen generation amount and the concentration of carbon monoxide that deteriorates the fuel electrode of the power generation cell 105, so that the output FO of the flow meters F1 to F5 described above, the evaporator 102, the reformer 103, and Based on each temperature measurement value T of the CO remover 104, the amount of fuel supplied to the reformer 103, the temperature of each part of the reforming unit, and the oxidant supplied to the CO remover 104 that removes carbon monoxide by an oxidation reaction Control the supply amount of (air). Further, since the catalytic combustion reaction is used as the heat source, the control unit 100 controls the supply amount of fuel and oxidant (air) supplied to the combustor 106 to maintain the reforming temperature. In addition, about the power supply system provided with such a fuel cell, it is disclosed by patent document 1, for example.

JP 200431280 A

  A power supply system including a reforming fuel cell may not have a configuration for directly detecting the concentration of carbon monoxide contained in the reformed gas, unlike the power supply system illustrated in FIG. 7 described above. In such a case, the amount of fuel supplied to the reformer 103 based on the output FO of the flow meters F1 to F5 and the temperature measurement values T of the evaporator 102, the reformer 103, and the CO remover 104. , The temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104), and the supply amount of oxidant (air) supplied to the CO remover 104 that removes carbon monoxide by an oxidation reaction. It is configured to strictly monitor and control.

  However, when the concentration of carbon monoxide contained in the reformed gas increases to about 50 ppm due to some factor and such reformed gas is supplied to the power generation cell 105, the power generation cell 105 is poisoned. As a result, the power generation performance is degraded. When the power generation cell is poisoned, it is usually necessary to perform a process for recovering the performance by filling the power generation cell 105 with air and removing carbon monoxide from the power generation cell by an oxidation reaction. A certain amount of time is required for recovery, and stable power generation operation is hindered.

  In other words, in other words, in a power supply system equipped with a reforming type fuel cell, when the concentration of carbon monoxide contained in the reformed gas is not directly detected, poisoning of the power generation cell is prevented in advance. There is a problem that can not be. In addition, since a sensor for monitoring the flow rate and temperature of each part and a number of valves for controlling the supply amount of fuel / air are required, there is a problem that the system is prevented from being downsized and reduced in cost. .

  Therefore, the present invention has been made in view of such circumstances, and a power supply system including a fuel cell that can suppress poisoning of a power generation cell and can achieve downsizing and cost reduction of the system. An object of the present invention is to provide a method for controlling the power supply system.

In order to achieve the above object, according to the first aspect of the present invention, a chemical reaction unit that generates a power generation gas by removing harmful components from a reformed gas obtained by reforming a power generation fuel by a reforming reaction . And a first power generation means for generating electric power by supplying the power generation gas; and a power generation apparatus that is provided between the chemical reaction unit and the first power generation means and that generates power by supplying the power generation gas. Second power generation means, a combustor, a fuel supply path for supplying the power generation gas to the first power generation means via the second power generation means, and bypassing the power generation gas to the combustor a bypass path for, when the electric power generated by the second power generating means according to the concentration of the harmful components of the power generation gas is lowered from the prescribed value, the supply of the pre-Symbol power generation gas from the fuel supply passage be characterized by including a toggle its control means to detour, the .

In the invention according to claim 2 subordinate to claim 1, the harmful component is carbon monoxide, and by detecting a decrease from a specified value of the power generated by the second power generation means, It is characterized by detecting an increase in the concentration of carbon monoxide in the gas.

In the invention according to claim 3 that depends on claim 1 or 2 , the first power generation means and the second power generation means include at least the fuel electrode formed on one surface of the electrolyte membrane and the other surface. The power generation gas is supplied to the fuel electrode.

The invention according to claim 4 that is dependent on claim 3 is characterized in that the second power generation means is formed in a size smaller than that of the first power generation means.

In the invention according to claim 5 subordinate to claim 3 or 4 , the harmful component is carbon monoxide, and each of the first power generation output means and the second power generation means is one of the electrolyte membranes. A first fuel electrode and a second fuel electrode formed on the surface, wherein the second fuel electrode generates power from the first fuel electrode with respect to the concentration of carbon monoxide in the power generation gas. It is characterized by comprising a catalyst having a large performance deterioration.

In an invention according to claim 6 , which is dependent on claim 5 , the second fuel electrode includes a Pt / C catalyst.

The invention according to claim 7 , which is dependent on claim 6 , is characterized in that the catalyst in the second fuel electrode has a smaller amount of Pt supported than the catalyst in the first fuel electrode.

In the invention according to claim 8 that depends on any one of claims 5 to 7, the power supply system is configured such that the second fuel electrode is poisoned by an increase in the concentration of carbon monoxide in the power generation gas. In this case, the apparatus includes an air supply means for supplying air to the second power generation means.

In the invention according to claim 9 , which is dependent on any one of claims 1 to 8, the control means supplies the power generation gas to the first power generation means via the second power generation means. A first switching valve provided in the fuel supply path, a second switching valve provided in the discharge path for discharging off-gas from the first power generation means, the first switching valve, and the second A detour path provided between the switching valves, the detour path and the discharge path are connected via the second switching valve, and the combustor is connected to the discharge path, In the case where a decrease from the specified value of the generated power by the second power generation means is not detected , the control means sets the first switching valve to the fuel supply path side and the second switching valve to the discharge path side. On the other hand, the generated power by the second power generation means If the drop from the specified value is detected, and characterized by interrupting the supply of the power generation gas to said first of said switching valve to route before Symbol bypass path side first power generation means To do.

In the invention according to claim 1 0 subordinate to any one of the claims 1 to 9, wherein the power supply system, the second power generating means are arranged in parallel a plurality, one of the second When the power generation means is supplied with the power generation gas, and the second power generation means detects a decrease in the generated power from the specified value according to the power generation gas, the other power generation means uses the power generation gas for the power generation. It is characterized by comprising switching means for switching so that gas is supplied.

In the invention according to claim 1 1, and the chemical reaction section which is removed to generate the power generation gas harmful components from the power generation fuel obtained by reforming reformed gas and generates electric power by the power generation gas a method of controlling a power supply system having a first power generation unit and the second power generation unit, wherein the power generation in the second generator means provided between said chemical reaction section the first power generating means gas is supplied, the steps of the second power generating means generates power, and sensing a change in the generated power in accordance with the power generation gas supplied to the second power generating means, the power generation gas If the drop from the specified value of the power generated by the second power generating means according to the concentration of the harmful components of the power generation gas in the step of detecting a change in the generated power in accordance with is detected, the first The power generation through the power generation means of 2 The use gas from a fuel supply path for supplying to the first power generation means, characterized by comprising the steps Ru switch, a to detour to bypass the power generation gas to the combustor.

In the invention according to claim 1 2 subordinate to the claims 1 1, wherein the harmful components is carbon monoxide, the step of detecting a change in the generated power in accordance with the power generation gas, the generated power of the prescribed value It is characterized in that an increase in the concentration of carbon monoxide in the power generation gas is detected by detecting a decrease in the power generation gas.

The invention according to claim 13, which is dependent on any one of claims 11, is characterized in that the control method of the power supply system is configured to detect the change of the generated power in the step of detecting a change in the generated power according to the power generation gas. And a step of controlling a reaction in the chemical reaction unit so as to reduce harmful components in the power generation gas when a decrease from a specified value is detected.

In the invention according to claim 14 subordinate to any one of claims 10 to 14, the step of controlling the reaction in the chemical reaction unit includes the step of controlling the temperature of the chemical reaction unit, and the chemical reaction unit. And a step of controlling the amount of power generation fuel and the amount of air supplied to the reaction section.

The invention of claim 15 when dependent on any one of the claims 1 1 to 14, the control method of the power supply system, the step of detecting a change in the generated power in accordance with the power generation gas And a step of recovering the ability to detect a change in the generated power when a decrease in the generated power from a specified value is detected.

In the invention according to claim 16 , a chemical reaction section that generates a power generation gas by removing harmful components from the reformed gas obtained by reforming the power generation fuel, and generates power using the power generation gas. In a control method of a power supply system having a first power generation means and a second power generation means,
Supplying the power generation gas to the second power generation means provided between the chemical reaction unit and the first power generation means, and the second power generation means generates electric power;
A step of detecting a change in the generated power in accordance with the power generation gas supplied to the second power generating means,
In the step of detecting the change in the generated power according to the power generation gas, a decrease from the specified value of the power generated by the second power generation means is detected according to the concentration of the harmful component in the power generation gas . If, from the fuel supply path for supplying to the first power generating means said power generation gas through the second power generation unit, the steps Ru switched to detour to bypass the power generation gas to the combustor,
In the step of detecting the change in generated power according to the power generation gas, if a decrease from the specified value of the generated power is detected, and if the temperature of the chemical reaction unit is appropriate, the chemical reaction unit Increasing the supply amount of air used to remove the harmful components in
In the step of increasing the supply amount of air in the chemical reaction section, after increasing the amount of air supplied to the chemical reaction section, detecting a change in generated power according to the power generation gas;
After increasing the amount of air supplied to the chemical reaction unit, in the step of detecting a change in the generated power according to the power generation gas, when detecting a decrease from the specified value of the generated power, the chemical reaction unit Returning the amount of air supplied in the step of increasing the amount of air in the step to reduce the amount of the fuel for power generation supplied to the chemical reaction section,
After the amount of the power generation fuel supplied to the chemical reaction unit is reduced in the step of reducing the amount of the power generation fuel supplied to the chemical reaction unit, a change in generated power corresponding to the power generation gas is detected. Steps, It is characterized by comprising.

The invention according to claim 17, dependent on the claim 1 6, wherein the harmful components is carbon monoxide, the step of detecting a change of the origination Denden force corresponding to the power generation gas, the provisions of the generated power A rise in the carbon monoxide concentration in the power generation gas is detected by detecting a decrease from the value .

  According to the first aspect of the present invention, the chemical reaction section that removes harmful components from the reformed gas obtained by reforming and reforming the power generation fuel to generate the power generation gas, and the power generation gas A first power generation means for generating electric power by being supplied; and a second power generation means for generating electric power by being supplied with a power generation gas, and the first power generation means based on a change in power generated by the second power generation means. Since the supply of the power generation gas to the fuel cell is controlled by controlling the supply of the power generation gas to the first power generation means without providing a sensor for detecting harmful components in the reformed gas. The power generation means) can be prevented from being poisoned, and the system can be reduced in size and cost.

According to the twelfth aspect of the present invention, a plurality of second power generation means are arranged in parallel, and a power generation gas is supplied to any one of the second power generation means, and the second power generation means uses the second power generation means for power generation . If a decrease in the specified value of the generated power in accordance with the gas is detected, and switched to power generation gas to the other of the second power generating means is supplied, the second power generating means has generated power decreases While recovering, the power generation operation by the first power generation means can be maintained.

According to the invention described in claim 16 , a change in harmful component in the power generation gas supplied from the chemical reaction unit to the power generation unit is detected based on a change in generated power corresponding to the power generation gas, When an increase in the concentration of water is detected, the supply of power generation gas to the power generation means is shut off, so that poisoning of the fuel cell (power generation means) can be suppressed.
Further, when an increase in the concentration of harmful components in the power generation gas is detected, if the temperature of the chemical reaction unit is appropriate, the supply amount of air used for removing carbon monoxide in the chemical reaction unit is increased. Then, after increasing the amount of air supplied to the chemical reaction section, the presence or absence of abnormal concentrations of harmful components in the power generation gas supplied from the chemical reaction section to the power generation section is detected, and abnormal carbon monoxide concentrations are detected. When detected, the supply amount of the increased air is restored, and the amount of fuel supplied to the chemical reaction unit is reduced. Subsequently, after reducing the amount of fuel supplied to the chemical reaction unit, the presence or absence of an abnormal concentration of harmful components in the power generation gas supplied from the chemical reaction unit to the power generation unit is detected. Therefore, it is possible to omit a part of the flow meter for measuring the fuel supply amount to the chemical reaction unit and the flow meter for measuring the air supply amount, thereby reducing the size and cost of the system. .

Embodiments of the present invention will be described below with reference to the drawings.
A. First Embodiment (1) Configuration FIG. 1 is a block diagram showing a configuration of a first embodiment of a power supply system according to the present invention. FIG. 2 is a diagram showing a state in which a route is set on the bypass road side in the first embodiment. In addition, the same number is attached | subjected to the same component as the prior art example shown in FIG. 7, and the description is abbreviate | omitted.
The power supply system shown in FIG. 1 is different from the conventional example shown in FIG. 7 in that a dummy power generation cell 200 is provided between a CO remover 104 (chemical reaction unit) and a power generation cell 105 (first power generation means). (Second power generation means), a switching valve 201 (first switching valve), 202 (second switching valve), a bypass path (detour) 300 connected between the switching valves 201, 202, and The configuration includes a valve V6 and a flow meter F6 for introducing air sent from the air pump P3 into the dummy power generation cell 200, and a control unit 100 (control means) is described later according to the output voltage of the dummy power generation cell 200. The system control is performed. Hereinafter, the configuration of the portion of the present embodiment that is different from the conventional example illustrated in FIG. 7 will be described.

The dummy power generation cell 200 has a structure similar to that of the power generation cell 105 in structure, and a fuel electrode (anode) formed on one surface of the electrolyte membrane MEA and an air electrode (cathode) formed on the other surface. Between the hydrogen contained in the reformed gas supplied from the CO remover 104 to the fuel electrode and the oxygen of the air introduced from the air pump P3 into the air electrode via the valve V6 and the flow meter F6. Electricity is generated by chemical reaction.
Here, normally, the fuel electrode of the power generation cell 105 has a CO poisoning-resistant catalyst (for example, capable of maintaining a certain level of power generation performance even at a relatively high concentration of carbon monoxide (hazardous component) (for example, 20 to 50 ppm)) Pt-Ru / C or the like) is used. However, the fuel electrode of the dummy power generation cell 200 is intentionally used as a low-performance power generation cell by using a catalyst that causes a decrease in power generation performance even at a low carbon monoxide concentration (for example, about 10 ppm). A Pt / C catalyst with poor toxicity, or a catalyst with reduced CO poisoning by reducing the amount of Pt supported is used. That is, the low-performance dummy power generation cell 200 that is easily poisoned is used as a sensor for detecting the carbon monoxide concentration, and is provided in the front stage of the power generation cell 105.

  The output voltage of the dummy power generation cell 200 is supplied to the control unit 100 as a sensor signal for detecting the carbon monoxide concentration. The control unit 100 determines whether or not the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 is increased based on the output voltage of the dummy power generation cell 200. The switching valve 201 is provided in a fuel supply path that supplies reformed gas (off gas) discharged from the dummy power generation cell 200 to the power generation cell 105. The switching valve 202 is provided in a discharge path for supplying off-gas discharged from the power generation cell 105 to the combustor 106. The switching valve 201 and the switching valve 202 are connected by a bypass passage 300.

  The switching valve 201 is switched to either the fuel supply path side or the bypass path 300 side according to the valve drive signal VD generated by the control unit 100. On the other hand, the switching valve 202 is switched to either the discharge path side or the bypass path 300 side according to the valve drive signal VD generated by the control unit 100.

  That is, the control unit 100 operates normally so that the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 does not increase below a specified value and the output voltage of the dummy power generation cell 200 does not decrease. In the middle, as shown in FIG. 1, the switching valve 201 is set on the fuel supply path side, and the switching valve 202 is set on the discharge path side. On the other hand, during an abnormal operation in which the carbon monoxide concentration in the reformed gas rises above the specified value and the output voltage of the dummy power generation cell 200 decreases, both the switching valve 201 and the switching valve 202 are shown in FIG. Are respectively set on the bypass path 300 side, and the reformed gas supply to the power generation cell 105 is shut off. Thereby, poisoning of the power generation cell 105 is suppressed.

  In addition, when the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 is increased, the dummy power generation cell 200 is poisoned and the output voltage is decreased. As described above, 100 is detoured so that the reformed gas is not supplied to the power generation cell 105 and supplied to the combustor 106. At the same time, the valve V6 is opened to restore the power generation performance of the poisoned dummy power generation cell 200. Then, air is supplied to the dummy power generation cell 200 to promote the oxidation reaction.

(2) Operation Next, the operation of the control unit 100 in the power supply system having the above configuration will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of the system control process executed by the control unit 100.
First, when the system is activated, the control unit 100 proceeds to step SA1 shown in FIG. 3 to monitor the output voltage of the dummy power generation cell 200, and based on the output voltage of the dummy power generation cell 200, the CO remover 104. To determine whether or not the carbon monoxide concentration in the reformed gas supplied to the dummy power generation cell 200 has increased.

  Here, if the output voltage of the dummy power generation cell 200 does not decrease from the predetermined specified value and no increase in the carbon monoxide concentration in the reformed gas is detected (during normal operation), the determination result in step SA1 is “ The process proceeds to step SA2, and as shown in FIG. 1, the switching valve 201 is set on the fuel supply path side and the switching valve 202 is set on the discharge path side, and the process returns to step SA1.

  On the other hand, when the output voltage of the dummy power generation cell 200 decreases from the predetermined specified value and an increase in the concentration of carbon monoxide in the reformed gas is detected (during abnormal operation), the determination result in step SA1 is “YES”. Proceed to step SA3. In step SA3, as shown in FIG. 2, both the switching valve 201 and the switching valve 202 are set on the bypass path 300 side, and the reformed gas supply to the power generation cell 105 is shut off. Thereby, poisoning of the power generation cell of the power generation cell 105 can be suppressed.

Next, during abnormal operation, a process is performed in which the carbon monoxide concentration is lowered and returned to a normal value. That is, in step SA4, it is determined whether or not the temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is within a normal range. If any of the temperatures of the evaporator 102, the reformer 103, and the CO remover 104 is out of the normal range, the determination result is “NO”, and the process proceeds to Step SA5. In step SA5, the amount of fuel and air supplied to the combustor 106 is adjusted.
That is, when the temperature of any part of the reforming unit is above the normal range, the valve V2 and the valve V3 are adjusted so as to reduce or cut the fuel and air supplied to the combustor 106. When the value is below the range, the valve V2 and the valve V3 are adjusted so that the amount of fuel and air supplied to the combustor 106 is increased. Thereafter, the process returns to step SA1.

  On the other hand, if the temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is within the normal range, the determination result of step SA4 is “YES”, and step SA6 is reached. move on. In step SA6, it is determined whether or not the amount of air supplied to the CO remover 104 is normal. If the amount of air supplied to the CO remover 104 is not normal, the determination result is “NO”, the process proceeds to step SA7, and the valve V4 is adjusted so that the amount of air supplied to the CO remover 104 is appropriate. Thereafter, the process returns to step SA1. On the other hand, if the amount of air supplied to the CO remover 104 is normal, the determination result is “YES”, and the flow proceeds to step SA8.

In step SA8, it is determined whether or not the fuel flow rate supplied to the evaporator 102 is normal. If the fuel flow rate supplied to the evaporator 102 is not normal, the determination result is “NO”, the process proceeds to step SA9, and after adjusting the valve V1 so that the fuel flow rate supplied to the evaporator 102 is appropriate, The process returns to step SA1.
On the other hand, if the fuel flow rate supplied to the evaporator 102 is normal, the determination result is “YES”, and the flow proceeds to step SA10. In step SA10, the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 has increased despite the fact that there is no abnormality in the temperature, air supply amount, and fuel supply amount of each part. In view of a failure or system error in any part of the power system, the system is shut down to stop the entire system, and at the same time, an alarm is generated and the process is terminated.

  As described above, in the first embodiment, the low-performance dummy power generation cell 200 that is easily poisoned is provided between the CO remover 104 and the power generation cell 105, and one of the reformed gases generated in the CO remover 104 is provided. When a rise in the carbon monoxide concentration contained in the reformed gas is detected by a decrease in the output voltage of the dummy power generation cell 200 when used as a sensor for detecting the carbon oxide concentration, as shown in FIG. Since both of the switching valves 202 are routed to the bypass passage 300 side and the reformed gas supply to the power generation cell 105 is shut off, it is possible to suppress poisoning of the power generation cell of the power generation cell 105. .

B. Modified Example In the above-described first embodiment, when the dummy power generation cell 200 is poisoned, as described above, both the switching valve 201 and the switching valve 202 are set on the bypass path 300 side (see FIG. 2). Thus, the reformed gas supply to the power generation cell 105 is shut off, while the power generation performance of the dummy power generation cell 200 is recovered. To restore the dummy power generation cell 200, the valve V6 is opened to fill the dummy power generation cell 200 with air sent from the air pump P3, and a recovery process is performed to remove carbon monoxide adhering to the catalyst. This recovery process requires a certain amount of time, and during that time, the reformed gas remains unsupplied to the power generation cell 105, which may impair stable power generation operation.

  Therefore, in the following, a modified example in which the power generation operation can be maintained while the poisoned dummy power generation cell 200 is recovered will be described. FIG. 4 is a block diagram showing a main configuration of a power supply system according to a modification of the first embodiment. The modification shown in this figure is different from the first embodiment shown in FIGS. 1 and 2 in that dummy power generation cells 200-1 to 200-1 arranged in parallel between the CO remover 104 and the power generation cell 105. 200-3, a switching valve 203 that supplies the reformed gas sent from the CO remover 104 to any one of the dummy power generation cells 200-1 to 200-3, and these dummy power generation cells 200-1 to 200-3. The switching valve 204 that selects any one of the off-gases discharged from the gas and outputs it to the next stage, and the control unit that switches the paths of the switching valves 203 and 204 according to the output voltages of the dummy power generation cells 200-1 to 200-3 100.

  In the above configuration, for example, when the dummy power generation cell 200-1 is poisoned by detecting an increase in the concentration of carbon monoxide in the reformed gas, as in step SA7 (see FIG. 3) in the first embodiment described above. Each path of the switching valves 203 and 204 is switched to the dummy power generation cell 200-2 side while adjusting the amount of air supplied to the CO remover 104 to reduce the concentration of carbon monoxide contained in the reformed gas. Thereby, dummy power generation cell 200-2 is used as a carbon monoxide concentration detection sensor, and the power generation performance of dummy power generation cell 200-1 poisoned during that time is recovered.

  In this way, if a plurality of dummy power generation cells 200 are arranged in parallel and the dummy power generation cell 200 functioning as a carbon monoxide concentration detection sensor is poisoned, other dummy power generations that are not poisoned. If the cell 200 is newly switched to be used as a carbon monoxide concentration detection sensor and the power generation performance of the poisoned dummy power generation cell 200 is restored, the power generation operation can be performed while the poisoned dummy power generation cell 200 is recovered. It becomes possible to maintain.

C. Second Embodiment (1) Configuration FIG. 5 is a block diagram showing a configuration of a power supply system according to a second embodiment of the present invention. In the power supply system shown in this figure, the same reference numerals are given to the same components as those in the first embodiment shown in FIG. 1, and description thereof will be omitted. The power supply system shown in FIG. 5 is different from the first embodiment shown in FIG. 1 in that the flow rate F1 for measuring the amount of fuel supplied to the evaporator 102 and the amount of air supplied to the CO remover 104 are measured. This is because the flow meter F4 is omitted.

  As a factor that causes an increase in the concentration of carbon monoxide in the reformed gas, when the air supply amount to the CO remover 104 is inappropriate, or when the methanol reaction rate decreases due to excessive fuel supply to the reformer 103, It has been known. Therefore, in the first embodiment described above, the air supply amount to the CO remover 104 is monitored by the flow meter F4, and the fuel supply amount to the evaporator 102 is monitored by the flow meter F1, respectively. In the second embodiment, system control for preventing an increase in the concentration of carbon monoxide in the reformed gas is performed based on the output voltage of the dummy power generation cell 200 while omitting these flow meters F1 and F4. The system control process according to the second embodiment will be described below with reference to FIG.

(2) Operation FIG. 6 is a flowchart showing the operation of the system control process in the second embodiment. First, when the system Ru is activated, the control unit 100 advances the process to Step SB1 shown in FIG. 6, on the basis of the output voltage of the dummy power generation cell 200, reformer supplied from the CO remover 104 in the dummy power generation cell 200 Determine if there is an increase in the concentration of carbon monoxide in the gas.

  Here, if the output voltage of the dummy power generation cell 200 does not decrease from the predetermined specified value and no increase in the carbon monoxide concentration in the reformed gas is detected (during normal operation), the determination result in step SB1 is “ The process proceeds to step SB2, and as shown in FIG. 5, the switching valve 201 is set on the fuel supply path side, the switching valve 202 is set on the discharge path side, and the process returns to step SB1 again.

  On the other hand, when the output voltage of the dummy power generation cell 200 decreases from a predetermined specified value and an increase in the concentration of carbon monoxide in the reformed gas is detected (during abnormal operation), the determination result in step SB1 is “YES”. Proceed to step SB3. In step SB3, as in the first embodiment described above, as shown in FIG. 2, both the switching valve 201 and the switching valve 202 are set on the bypass path 300 side, and the reformed gas to the power generation cell 105 is set. Shut off the supply. Thereby, poisoning of the power generation cell of the power generation cell 105 can be suppressed.

Next, in step SB4, it is determined whether or not the temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is within a normal range. If any of the temperatures of the evaporator 102, the reformer 103, and the CO remover 104 is out of the normal range, the determination result is “NO”, and the process proceeds to Step SB5. In step SB5, the amount of fuel and air supplied to the combustor 106 is adjusted.
That is, when the temperature of any part of the reforming unit is above the normal range, the valve V2 and the valve V3 are adjusted so as to reduce or cut the fuel and air supplied to the combustor 106. When the value is below the range, the valve V2 and the valve V3 are adjusted so that the amount of fuel and air supplied to the combustor 106 is increased. Thereafter, the process returns to step SB1 described above.

  On the other hand, if the temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is within the normal range, the determination result in step SB4 is “YES”, and step SB6 is performed. move on. In step SB6, the valve V4 is adjusted to increase the amount of air supplied to the CO remover 104. That is, when the carbon monoxide concentration in the reformed gas is increased, if the temperature of each part of the reforming unit (evaporator 102, reformer 103, and CO remover 104) is within the normal range, CO removal Since it is considered that the amount of air supplied to the vessel 104 is insufficient, the valve V4 is adjusted so as to increase the amount of air supplied to the CO remover 104.

Subsequently, in step SB7, based on the output voltage of the dummy power generation cell 200, it is determined whether or not the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 is normal. If the carbon monoxide concentration is normal, the determination result is “YES”, and the process returns to step SB1.
On the other hand, if the carbon monoxide concentration is not normal, the determination result is “NO”, the process proceeds to step SB8, and the valve V4 is adjusted so that the air supply amount to the CO remover 104 is restored. In step SB9, the valve V1 is adjusted to reduce the amount of fuel supplied to the evaporator 102.

Next, in step SB10, based on the output voltage of the dummy power generation cell 200, it is determined whether the carbon monoxide concentration in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 is normal. If the carbon monoxide concentration is normal, the determination result is “YES”, and the process returns to step SB1.
On the other hand, if the carbon monoxide concentration is not normal, the determination result is “NO”, the process proceeds to step SB11, and the valve V1 is adjusted so that the fuel supply amount to the evaporator 102 is restored. In step SB12, carbon monoxide in the reformed gas supplied from the CO remover 104 to the dummy power generation cell 200 even if the air supply amount to the CO remover 104 and the fuel supply amount to the evaporator 102 are adjusted. Since the concentration has increased, it is regarded as a failure or system error in any part of the power supply system, and the system is shut down to stop the entire system. At the same time, an alarm is generated and the process is terminated.

  As described above, in the second embodiment, similarly to the above-described first embodiment, when the increase in the concentration of carbon monoxide contained in the reformed gas is detected due to the decrease in the output voltage of the dummy power generation cell 200, the switching valve 201 is used. Since both the switching valve 202 and the switching valve 202 are respectively set on the bypass path 300 side and the reformed gas supply to the power generation cell 105 is shut off, poisoning of the power generation cell of the power generation cell 105 can be suppressed.

  In addition, it is determined whether or not the carbon monoxide concentration contained in the reformed gas is normal from the output voltage of the dummy power generation cell 200. If not, the amount of air supplied to the CO remover 104 is increased or evaporated. Since the process of reducing the fuel supply amount to the evaporator 102 is performed to remove the factor causing the increase in the concentration of carbon monoxide, the flow meter F1 for measuring the fuel supply amount to the evaporator 102 and the air supply to the CO remover 104 The flow meter F4 for measuring the amount can be omitted, which makes it possible to reduce the size and cost of the system.

  In the second embodiment, an example in which one dummy power generation cell 200 is provided between the CO remover 104 and the power generation cell 105 has been described. However, the present invention is not limited to this, and the modification example of the first embodiment described above may be used. Similarly, when a plurality of dummy power generation cells 200 are arranged in parallel between the CO remover 104 and the power generation cell 105 and the dummy power generation cell 200 functioning as a carbon monoxide concentration detection sensor is poisoned, If the other dummy power generation cell 200 that is not poisoned is newly switched to be used as a carbon monoxide concentration detection sensor and the power generation performance of the poisoned dummy power generation cell 200 is restored, the poisoned dummy power generation cell 200 The power generation operation can be maintained while the cell 200 is recovered.

It is a block diagram which shows the structure of 1st Embodiment of the power supply system which concerns on this invention. It is a figure which shows the state set to the bypass road side in 1st Embodiment. It is a flowchart which shows the operation | movement of the system control processing by 1st Embodiment. It is a block diagram which shows the principal part structure of the modification of 1st Embodiment. It is a block diagram which shows the structure of 2nd Embodiment of the power supply system which concerns on this invention. It is a flowchart which shows the operation | movement of the system control process by 2nd Embodiment. It is a block diagram which shows the example of a conventional structure of a power supply system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Control part 101 Fuel tank 102 Evaporator 103 Reformer 104 CO remover 105 Power generation cell 106 Combustor P1-P3 Pump V1-V6 Valve F1-F6 Flow meter

Claims (17)

A chemical reaction section that generates a power generation gas by removing harmful components from the reformed gas obtained by reforming the power generation fuel through a reforming reaction;
First power generation means for generating power by being supplied with the power generation gas;
A second power generation means that is provided between the chemical reaction unit and the first power generation means, and is supplied with the power generation gas to generate electric power;
A combustor,
A fuel supply path for supplying the power generation gas to the first power generation means via the second power generation means;
A detour that bypasses the power generation gas to the combustor;
Control means for switching the supply of the power generation gas from the fuel supply path to the bypass when the power generated by the second power generation means is reduced from a specified value in accordance with the concentration of the harmful component in the power generation gas. When,
A power supply system comprising:   The harmful component is carbon monoxide, and an increase in the concentration of carbon monoxide in the power generation gas is detected by detecting a decrease from a specified value of power generated by the second power generation means. The power supply system according to claim 1.   The first power generation means and the second power generation means include at least a fuel electrode formed on one surface of the electrolyte membrane and an air electrode formed on the other surface, and the power generation gas is provided on the fuel electrode. The power supply system according to claim 1, wherein the power supply system is supplied.   4. The power supply system according to claim 3, wherein the second power generation means is formed to have a size smaller than that of the first power generation means.   The harmful component is carbon monoxide, and the first power generation unit and the second power generation unit each include a first fuel electrode and a second fuel electrode formed on one surface of the electrolyte membrane. The said 2nd fuel electrode is equipped with the catalyst whose power generation performance fall is larger than the said 1st fuel electrode with respect to the carbon monoxide density | concentration in the said gas for electric power generation, The Claim 3 or 4 characterized by the above-mentioned. Power system.   The power supply system according to claim 5, wherein the second fuel electrode includes a Pt / C catalyst.   The power supply system according to claim 6, wherein the catalyst in the second fuel electrode has a smaller amount of Pt supported than the catalyst in the first fuel electrode.   The power supply system includes air supply means for supplying air to the second power generation means when the second fuel electrode is poisoned due to an increase in the concentration of carbon monoxide in the power generation gas. The power supply system according to claim 5, wherein the power supply system is a power supply system. The control means includes: a first switching valve provided in a fuel supply path for supplying the power generation gas to the first power generation means via the second power generation means; and a first switching valve from the first power generation means. A second switching valve provided in a discharge path for discharging off-gas, and a bypass provided between the first switching valve and the second switching valve,
The detour and the discharge path are connected via the second switching valve, and the combustor is connected to the discharge path,
In the case where a decrease from the specified value of the generated power by the second power generation means is not detected, the control means sets the first switching valve to the fuel supply path side and the second switching valve to the discharge path. On the other hand, when a decrease in the generated power from the specified value by the second power generation means is detected, the first switching valve is routed to the detour side and the first switching valve is set. The power supply system according to any one of claims 1 to 8, wherein supply of the power generation gas to the power generation means is shut off.   In the power supply system, a plurality of the second power generation means are arranged in parallel, the power generation gas is supplied to any one of the second power generation means, and the second power generation means responds to the power generation gas. 10. A switching means for switching so that the power generation gas is supplied to the other second power generation means when a decrease from the specified value of the generated power is detected. The power supply system according to any one of the above. A chemical reaction unit that generates a power generation gas by removing harmful components from the reformed gas obtained by reforming the power generation fuel, and a first power generation unit and a second power generation unit that generate power using the power generation gas. A control method for a power supply system comprising:
The power generation gas is supplied to the second power generation means provided between the chemical reaction unit and the first power generation means, and the second power generation means generates power,
Detecting a change in generated power according to the power generation gas supplied to the second power generation means;
When a decrease in the generated power from the specified value by the second power generation means is detected in accordance with the concentration of the harmful component in the power generation gas in the step of detecting a change in power generation according to the power generation gas. And switching from a fuel supply path for supplying the power generation gas to the first power generation means via the second power generation means to a bypass for bypassing the power generation gas to a combustor;
A control method for a power supply system, comprising: The harmful component is carbon monoxide, and the step of detecting a change in the generated power according to the power generation gas is performed by detecting a decrease from the specified value of the power generation power to detect the concentration of carbon monoxide in the power generation gas. 12. The method of controlling a power supply system according to claim 11, wherein an increase in the power is detected. The control method of the power supply system is configured to detect harmful components in the power generation gas when a decrease from a specified value of the power generation power is detected in the step of detecting a change in power generation power according to the power generation gas. The method of controlling a power supply system according to claim 11, further comprising a step of controlling a reaction in the chemical reaction unit so as to decrease. The step of controlling the reaction in the chemical reaction part includes:
Controlling the temperature of the chemical reaction section;
Controlling the amount of fuel for power generation and the amount of air supplied to the chemical reaction section;
14. The method of controlling a power supply system according to claim 12, further comprising: The control method of the power supply system is capable of detecting a change in the generated power when a decrease from the specified value of the generated power is detected in the step of detecting a change in the generated power according to the power generation gas. the method of the power supply system according to any one of claims 1 1 to 14, characterized by including the step of restoring. A chemical reaction unit that generates a power generation gas by removing harmful components from the reformed gas obtained by reforming the power generation fuel, and a first power generation unit and a second power generation unit that generate power using the power generation gas. A control method for a power supply system comprising:
Supplying the power generation gas to the second power generation means provided between the chemical reaction unit and the first power generation means, and the second power generation means generates electric power;
Detecting a change in generated power according to the power generation gas supplied to the second power generation means;
In the step of detecting the change in the generated power according to the power generation gas, a decrease from the specified value of the power generated by the second power generation means is detected according to the concentration of the harmful component in the power generation gas. A step of switching from a fuel supply path for supplying the power generation gas to the first power generation means via the second power generation means to a bypass for bypassing the power generation gas to a combustor;
In the step of detecting the change in generated power according to the power generation gas, if a decrease from the specified value of the generated power is detected, and if the temperature of the chemical reaction unit is appropriate, the chemical reaction unit Increasing the supply amount of air used to remove the harmful components in
In the step of increasing the supply amount of air in the chemical reaction section, after increasing the amount of air supplied to the chemical reaction section, detecting a change in generated power according to the power generation gas;
After increasing the amount of air supplied to the chemical reaction unit, in the step of detecting a change in the generated power according to the power generation gas, when detecting a decrease from the specified value of the generated power, the chemical reaction unit Returning the amount of air supplied in the step of increasing the amount of air in the step to reduce the amount of the fuel for power generation supplied to the chemical reaction section,
After the amount of the power generation fuel supplied to the chemical reaction unit is reduced in the step of reducing the amount of the power generation fuel supplied to the chemical reaction unit, a change in generated power corresponding to the power generation gas is detected. Steps,
A control method for a power supply system, comprising:   The harmful component is carbon monoxide, and the step of detecting the change in the generated power according to the power generation gas is performed by detecting a decrease from a specified value of the power generation power. 17. The method of controlling a power supply system according to claim 16, wherein an increase in concentration is detected.

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